Abstract. The capture of two female specimens of white grouper, Epinephelus aeneus (GEOFFROY ST HILAIRE, 1817) (Perciformes, Serranidae), north of Corsica, is the first record for the French waters and the north-western Mediterranean Sea. The first specimen, a mature individual (TL = 540 mm), was caught in the Gulf of Saint-Florent, whereas the second one, an immature individual (TL = 460 mm), south of Bastia (Tyrrhenian Sea).

As marine fisheries resources around the world are increasingly threatened by pollution, climate change, and overfishing, it is more important than ever to know the amount and types of fish and invertebrates being extracted from the marine environment. Fisheries resources, particularly for island countries, provide a crucial source of food and income. However, the very fisheries which depend on these natural goods and services—notably small-scale fisheries—are being under-represented in fisheries statistics. In many of the countries highlighted in this report, the majority of seafood consumed is taken via subsistence fisheries. This non-commercial fishing sector is largely overlooked in statistical collection systems, particularly those of several decades ago, but continues to be under-represented today. In some places this is beginning to change, as the importance of small-scale fisheries to national food security is being recognized.

In many developing countries, which lack the infrastructure and resources to fish their own waters for economic development through trade with external markets, foreign access fees are collected as a key source of revenue. In exchange for a modest fee, foreign fleets are allowed to fish their waters for high valued species. While this provides much needed income for the country, it also threatens the availability of these resources for domestic sustenance.

While there is a range in the quality of fisheries reporting from one country to the next, in almost all countries Illegal, Unreported and Unregulated (IUU) fisheries exist. Fisheries landings statistics, as supplied to the United Nation‘s Food and Agriculture Organization (FAO), represent mainly the commercial and larger-scale fisheries. Artisanal, subsistence and recreational fisheries are mostly overlooked. Discarded bycatch and baitfish associated with certain fishing techniques are also rarely included in the official statistics.

As a follow up to Fisheries Catch Reconstructions: Islands, Part I, this report continues to reconstruct total marine fisheries catches of island countries around the world from 1950 to present. This edition describes fisheries for island countries in the Pacific, Indian and Atlantic Oceans, highlighting the discrepancies that exist between reported landings and likely true catches. The reconstruction approach used here, as in the previous edition, aims to estimate all marine fisheries extractions as a baseline for monitoring and management purposes in the face of continued anthropogenic pressures. The future success of these countries relies, in part, on their ability to keep pace with an increasingly gl0bal economy while maintinaing a healthy supply of resources for domestic purposes.

gSea Around Us Project, Fisheries Centre, University of British Columbia, 2202 Main Mall, Vancouver V6T 1Z4, Canada, d.pauly@fisheries.ubc.ca

ABSTRACT

Corsica is an island in the Western Mediterranean belonging to France, located southeast of the French mainland and west of Italy. The island covers an area of about 8,700 km2, is flanked by deep water along its west coast, and by a broad shelf along its east coast. Corsica has fisheries in its coastal lagoons, but its most commercially important fishery is the red spiny lobster (Palinurus elephas) fishery, followed by bottom trawling for finfish. Other smaller and poorly documented artisanal and recreational fisheries also occur, but overall fishing pressure appears to be low, and the number of full time fishers is declining. The total reconstructed catch from 1950 to 2008 was 118,700 tonnes - 5 times more than the 23,700 tonnes reported by France to FAO – of which 30% was unreported recreational catch by locals or tourists, 37% was bottom-trawl catch, 10% was associated bycatch (unreported, landed or discarded), and 23% was red spiny lobster and pelagic catches. The estimated mean annual catch in the 21st century was 1,300 tonnes. Field investigations are needed to improve on these data, presented here as a first approximation of total extractions from the waters surrounding Corsica.

INTRODUCTION

Corsica is the fourth largest island of the Mediterranean and a part of France. It is located southeast of the French mainland and north of Sardinia (Italy), and west of the Italian Peninsula (42° N and 9° E; Figure 1). Corsica is characterized by a mountainous landscape and a highly disparate underwater morphology, featuring a steep descent to depth along the western part of the island (down to 3,000 m, 10 km offshore). In contrast, wide expanses of shallow waters are present along the east coast, where a depth of only 150 m has been recorded 11 km offshore, and several lagoons important for the Island‘s marine fisheries are also found along the east coast (Riutort, 1994).

Corsican waters host numerous fish and invertebrate species (de Caraffa, 1929; Miniconi, 1989, 2001) and valuable habitats (e.g., meadows of seagrass Posidonia oceanica), of which most are protected under European Commission directives or national legislations (Anon., 1975; 1979, 1981, 1987, 1992, 1994, 1999) (Figure 1). The Réserve Naturelle des Bouches de Bonifacio is the largest marine protected area (MPA) of metropolitan France, covering approximately 800 km² (Figure 1), including a 13 km² no-take zone and 130 km² with restricted fisheries activities. Regulations and monitoring seem to be effective, as increasing catches have been reported in and around this MPA (Santoni and Culioli, unpub. data)

Figure 1: Map of Corsica and its territorial waters (solid black line). Marine Protected Areas (blue areas and grey solid dots) are designated at a state level and aim to protect both habitats and wildlife by controlling, or even excluding human activities (no-take zones). Natura2000 zones (blue stripes) are designated at a European level and aim to protect both habitats and wildlife, without excluding human activities. The level of protection in the Natura2000 zones is lower than for MPAs. Source: www.affaires-maritimes.mediterranee.gov.fr

Since the 1950s, tourists have been attracted to Corsica for its natural beauty and pristine habitats, and the tourist population currently reaches 3 million per year (Anon., 2010), with a resident Corsican population of less than 300,000. The tourism industry has a major impact on seafood consumption and hence on marine resources, as already highlighted in the 1960s (Maurin, 1965). Currently, numerous hotels and/or charter companies offer recreational fishing opportunities, separate or in combination with consumption of local seafood.

Despite its potential attractiveness for fishers, the waters around Corsica have never experienced heavy industrial fishing pressure, and the history of Corsican resource extraction was shaped more by land-based than maritime activities. Therefore, there is almost no export of seafood out of Corsica, and a substantial fraction of the seafood consumed locally by Corsicans is imported from the French mainland or other Mediterranean countries. Currently, the number of professional fishers is declining, and Corsica likely experiences the lowest commercial fishing pressure in the Mediterranean Sea (Riutort, 1994; Relini et al., 1999). As a consequence, fisheries have generally not received much attention, and quantitative analyses of fisheries are scarce, except for the high-profile fishery for red spiny lobster (Palinurus elephas) (Pere et al., 2007; 2010) and for MPA fisheries (Rigo, 2000; Santoni, 2002; Mouillot et al., 2007; Rocklin et al., 2009).

Corsica - via France - has only supplied fisheries statistics to the Food and Agriculture Organization of the United Nations FAO since 1970. This study therefore aims to reconstruct Corsican fisheries catches back to 1950, while ensuring that all extractions due to fishing are considered, following the catch reconstruction approach of Zeller and Pauly (2007). Like most countries in the Mediterranean, France has not declared a formal Exclusive Economic Zones for its Mediterranean coast (EEZ; Anon., 1976; Santoni, 2002; Cacaud, 2005). Hense, our estimates of historical catches for the period 1950 to 2008 are deemed to have come from Corsican EEZ-equivalent waters.

Baseline data were extracted from the General Fisheries Commission for the Mediterranean (GFCM) section of the FAO FishStat database (FAO, 2009). As Corsica is remote from the French mainland, we assumed that all catches reported by France within the ‗Sardinia‘ FAO fishing area (Division 37.1.3) were Corsican. A bibliographical review of all Corsican fisheries was done to identify the ‗anchor points‘ required for inferences on historical catches back to 1950 (Zeller and Pauly, 2007). Data sources included peer-reviewed scientific articles, reports by local institutions, theses and other unpublished accounts, and local expert knowledge.

Total Corsican population

Population statistics were extracted from the National Institute of Statistics and Economic Studies (INSEE, www.insee.fr/fr/themes/theme.asp?theme=2&sous_theme=1&nivgeo=6&type=3 [accessed: October 15, 2010]). Population data were used here to indirectly estimate total catches by local residents (see ‗recreational fisheries: residents and tourists‘ sub-section; Figure 2a).

Fishers and fishing vessels in Corsica

The time-series of the population of fishers was obtained from Riutort (1994), and linear interpolations were applied between anchor points for years without data (Figure 2b). The number of fishers after the last anchor point (1993) was calculated by applying the trend in the number of fishers per vessel during the period 1950-1993 to the number of vessels for the period 1994-2008. It is worth noting that these vessels are usually smaller than 15 m, and operate close to shore (Miniconi, 1994; Riutort, 1994; Rigo, 2000; Santoni, 2002). The fishing industry in Corsica is therefore more artisanal than industrial, with small vessels (Riutort, 1994), short periods at sea, and a small supply chain (Riutort, 1989). The two time-series in Figure 2b were used to estimate bottom-trawl catches for the 1950-1970 period (see ‗artisanal demersal fishery‘ sub-section).

Figure 2. Basic statistics on Corsica: a) total resident Corsican population and b) trends in the number of fishers and vessels in Corsica. Anchor points are represented by closed circles.

Lobster fishery

Red spiny lobster (Palinurus elephas) is mainly exploited along the west coast of Corsica, where its preferred hard-bottom habitats are found. The fishery for lobster is relatively small, and vessels stay close to the coast, fishing at depths not exceeding 200 m (Marin, 1987). The fishery was profitable very early on (de Caraffa, 1929), but it is not well documented. Thus, official catch data are deemed inaccurate, and is at best a refelction of trends (Marin, 1987). Here, we attempt to re-estimate lobster catches for the entire 1950-2008 period using various sources of information.

Statistics were extracted from the Office de l’Environnement Corse (2010) for the 1950-1983 period. The early values (1950s) are in accordance with catches at the beginning of the 20th century, i.e., around 300 t·year-1 (Doumenge, 1956). For the 1983-2008 period, values were extracted from studies by Riutort (1999), Marin (1987) and Pere et al. (2010).

Changes in gears had an influence on both catch per unit of effort (CPUE) and discard rates (non-marketable lobsters). In the early 1960s, the traps in common use were replaced by trammelnets (Miniconi, 1989), which had higher CPUE, but also generated a higher discarding rate. Discards for traps were estimated to be about 5% during the 1950-1964 period (Riutort, unpub. data). During the 1965-1980 period, fishers were using trammelnets for short trips, and a discard rate of 12.5% was therefore used (Riutort, unpub. data). For the 1981-1994 period, the mean value of 15.7% between the 1965-1980 period (12.5%) and the 1995-1999 period (20%) was used (Riutort, 1999; Pere et al., 2010). For the 2000-2003 period, the same value of 12.5% was used. For the 2004-2007 period, Pere et al. (2010) estimated a discarding rate of 11.4%, which was also used for the year 2008.

It is worth noting here that two types of trammelnets are used in Corsica, to target either demersal fish (since before 1950) or red spiny lobster (since the early 1960s). Even when ‗lobster trammelnets‘ are used, a considerable amount of the bycatch is fish. Thus, 55% of total catch were fish species in 2008 (Riutort, 1989; 1994; Santoni and Culioli, unpub. data). This bycatch of fish is retained and landed, and was included in the next sub-section (artisanal demersal fisheries).

Artisanal demersal fisheries

Demersal species are caught in Corsican waters with two types of gears: trammelnets and bottom-trawlers. Trammelnets have been in use for demersal fish for a long time (prior to 1950), while we assumed bottom-trawlers were introduced in the early 1950s (Riutort, 1994). Catches by trammelnets may represent 50% of total fish catches in the province of Bonifacio (Santoni and Culioli, unpub. data), and given that no other studies were available, we used this 50% ratio for the 1965-2008 time-period and the entire island. Thus, the remaining 50% of demersal fish catches were treated as caught by bottom-trawlers as of 1965. For 1950, we set bottom-trawl fish catches as zero, and interpolated linearly to 1965. FAO FishStat contains data on demersal species for the period 1970-1992 only. In the absence of any alternative, we considered these data to be realistic. Indeed, none of the documents available on Corsican fisheries allowed us to make an independent estimate of the bottom-trawl and trammelnet fisheries catches.

Catches per fisher and catches per vessel (CPUE) for the period 1970-1992 were calculated by dividing catches of bottom-dwelling fish reported to FAO by the number of fishers or vessels (Figure 2b). CPUE for the 1950-1970 and 1993-2008 periods were then estimated by extrapolation of the trends of 1970-1992 CPUE time-series. The resulting CPUE data for the 1950-1970 and 1993-2008 periods were then multiplied by the number of fishers or vessels (Figure 2). Our estimate of total catch used the average values of these two catch time-series (one based on CPUE per fisher, one on CPUE per boat), which was then split evenly to create the bottom-trawl and trammelnets components.

Trammelnet fishery

The taxonomic breakdown of trammelnet commercial species in the Bonifacio MPA (Figure 1) was studied by Mouillot et al. (2007) from 2000 to 2006. Given that there were no other studies available that included a taxonomic breakdown, we assumed that the percentage of each species remained the same for the entire 1950-2008 time-period, and were similar for the entire island. A recent study concluded that trammelnet discards were representing approximately 10% of total catches, in the MPA of Bonifacio (Rocklin et al., 2009). These discards are composed of damaged, non-marketable fish. We used this study to estimate the taxonomic breakdown of these discards.

We assumed that the species composition of landed bottom-trawl catches were similar to the trammelnet fishery. However, we acknowledge that the species composition can vary significantly between the continental shelf and the slope. For higher depths (on the slope), many other species such as Nephrops norvegicus, Etmopterus spinax, Galeus melastomus, Merluccius merluccius or Trigla lyra can indeed account for a large part of the catch (Riutort, pers. obs.; Le Manach, pers. obs.). However, as it was not possible to estimate the percentage of each species or the importance of slope bottom-trawling, we did not take these observations into account. To estimate the bycatch by the artisanal bottom-trawl fishery, we used a bycatch rate of 40%, given by Machias et al. (2001) and Sanchez et al. (2004) for geographically close and similar fisheries. The MEDITS database (Bertrand et al., 1998) - 2009 update - was used to estimate the bycatch taxonomic breakdown. We assumed that non-commercial species occurring in this database were bycatch species, e.g., Spicara spp., Scyliorhinus spp., Raja spp., Micromesistius poutassou, Capros aper. Furthermore, as fishers land a portion of non-targeted bycatch, notably for their personal consumption and soupe de roche (‗rockfish soup‘), we conservatively assumed that 20% of the bycatch was landed, but unreported, and that the remainder (80%) was discarded.

Recreational fisheries: residents and tourists

To estimate recreational catches by Corsicans, we used a ‗Fermi solution‘, i.e., an approach pioneered by the physicist Enrico Fermi, to estimate unknown quantities from limited data (von Baeyer, 1993; Pauly, 2010). Thus, based on local knowledge (Culioli, pers. obs.; Riutort, pers. obs.), we estimated three anchor points, for 1950, 1980 and 2008. For 1980, we assumed that 30% of the total population, i.e., 76,000 out of 255,000 inhabitants, was potentially recreational fishers. Of these potential fishers, we assumed that 15% were actually fishers, and that they were on average fishing once a month, with yields of 4 kg per trip. For 2008, we used the same assumption that 30% of the total population, i.e., 84,000 out of 280,000 inhabitants, were potentially recreational fishers, but that the proportion of actual fishers increased to 25%. As local residents report that there are less fish now than in the 1980s, we assumed that fishers currently fish on average only 10 times a year, with yields of 1 kg per trip. For 1950, we assumed a stable CPUE and fishing effort compared to 1980, and derived total catches from the total population size.

Similarly, our estimate of recreational catches by tourists was based on the annual number of tourists, and assuming that sport fishing became more attractive in the 1990s. We conservatively assumed that 5% of tourists were catching on average 1 kg·year-1 for the 1950-1990 period, and that 8% of tourists were catching on average 1.5 kg·year-1 for the 1991-2008 period. Given that each tourist currently stays on average 10.3 days in Corsica, these assumptions seem reasonable (Anon., 2010).

Pelagic fisheries

Three pelagic fisheries are taking place in Corsican waters. However, information is scarce and no studies enabled us to re-estimate their total catches. Therefore, we included data as provided to FAO in our total reconstruction (except for small pelagics – see below).

Swordfish

Swordfish (Xiphias gladius) started to be targeted by artisanal longliners in the 1980s (Regional Committee of Corsican Marine Fisheries, 2009; Riutort, unpub. data). However, as tonnages are likely small (15-20 t·year-1; Riutort, unpub. data), it is possible that these catches are accounted for in official FAO statistics as ‗marine fish nei‘ (FAO, 2009).

Small pelagics

"Blue fish" (i.e., sardines, anchovies and mackerels) are also fished along the Corsican coast. Several studies report substantial catches during the 1960s and 1970s in Corsica and along the French mainland (Maurin, 1965; Bonnet, 1973; Pichot and Aldebert, 1978). It is worth noting that FAO data include sardine statistics only for 1972-1976 and 2006; data for other years being either non-existent or unrealistically

low. However, older Corsican residents remember very abundant sardine and anchovy catches during the 1950-1960s, most of which were exported to the mainland (Riutort, unpub. data). For the period 1950-1971, we therefore used the average catches for the period 1972-1976, and kept the rest of the time-period unchanged.

Maurin (1965) reports 100 tonnes of tuna caught in 1963 by Corsicans. However, he suggests that the tourism industry already accounted for a significant part of unreported catches, although he did not elaborate on this topic. Tuna may also be reported to FAO as ‗marine fish nei‘, and annual catches are likely very low or up to 15 tonnes (Riutort, unpub. data).

RESULTS AND DISCUSSION

Figure 3: Reconstructed catches of lobsters and associated discards for Corsica, 1950-2008. The dotted line represents official lobster landings data supplied to FAO.

Lobster fishery

As expected, our lobster catch reconstruction is very different from official statistics: our values are on average 16 times higher than data provided to FAO, and show a very different pattern over time (Figure 3). Lobster catches decreased from 300 t·year-1 in 1954 to 80 t·year-1 for 1959-1960. Then, catches increased again to 300 t·year-1 by 1962. At this time, a new (unspecified) crash occurred and catches dropped to 100 tonnes annually, staying at that level until the late 1970s. By 1984, catches increased to 250 t·year-1. Since then, catches have been decreasing, reaching 80 t·year-1 by the early 2000s. However, it is worth noting that catches currently seem to be increasing. Overall, the trend of the number of fishers and vessels (Figure 2b), and lobster catches (Figure 3) show a similar pattern, which confirms that this fishery is of great importance in Corsica and largely accounts for much of the fishing pressure.

Fluctuations in lobster catches may be partly explained by new policies and gear modifications, along with biological features (e.g., larval migration; Pere et al., 2011). The first crash in the 1950s likely resulted from increasing fishing pressure, and the following increase in catches is likely the result of a gear change from traps to trammelnets, which increased the CPUE. In 1968, policy-makers decided to close the lobster fishery between the 1st of October and 28th of February each year, which probably played a significant role in the stabilization of catches during the 1970s. Finally, new vessels were introduced in the early 1980s and were responsible for increased fishing effort. This increase is likely to have contributed to the increase in catches until 1984, then to the decrease in catches observed until the mid-2000s.

Figure 4: Reconstructed catches and associated bycatch (landed and discarded) for the demersal finfish fishery by the two main gears (trammelnet and bottom-trawler) in Corsica, 1950-2008. The dotted line represents official landings data supplied to FAO.

In the late 1970s, nine small marine protected areas (some of them no longer existing; Figure 1) were created, which also possibly led to the catch increases in the late 1970s early 1980s (Figure 3). The current decrease, which started around 1984, may be due to several factors, such as the decreasing number of fishers, or increasing fishing effort. It seems there is an increase in catches during the last few years. Such an increase could be due to biological parameters (e.g., larval migration), but no data were available to assess the validity of this assumption.

Artisanal demersal fishery

Demersal catches totaled an estimated 56,500 tonnes, compared to only 18,800 tonnes reported to FAO (Figure 4). Catches fluctuated, but declined overall from approximately 1,300 t·year-1 in 1950 to 500 t·year-1 in the late 2000s. Bycatch followed a different trend, totaling 10,300 tonnes and peaking around 250 t·year-1 in the 1980s due to the increasing number of trawlers. Bycatch amounts in the 1950s and the 2000s are similar, slightly above 100 t·year-1 (Figure 4).

Unlike our reconstruction for the lobster fishery (above), the reconstruction of artisanal bottom-trawl fishery catches was mainly based on official statistics. The main novelty in this result comes from the gaps in time-series originally supplied to FAO being filled in. Also, a significant part of total catches (18%) were previously unreported and are now reported as bycatch (either discarded or landed; Figure 4).

Recreational fisheries: residents and tourists

Recreational fisheries were estimated to catch 35,150 tonnes, of which 80% was taken by local resident fishers, and 20% by tourists (Figure 5). These catches were previously not included in statistics provided to FAO.

Based on our assumptions, we estimated that recreational catches by residents were the highest in 1950, with 612 t·year-1, and then declined to 210 t·year-1 by 2008 (Figure 5). On the other hand, recreational catches by tourists were estimated to have increased during the last two decades, increasing from 17 t·year-1 in 1950 to 360 t·year-1 by 2008 (Figure 5).

Figure 6: Catches in Corsican waters, showing a) reconstructed total catches versus landings data as supplied to FAO; and b) taxonomic breakdown (top 10 species) of reconstructed total catches in Corsica, 1950-2008. The ‗others‘ group includes Scorpaena scofa, Phycis spp., Pagellus, spp., Labridae, Serranus spp., Seriola dumerili, Zeus faber, as well as other fish species of lower importance in term of percentage, and species of invertebrates.

Reconstructed total Corsican fisheries catches total over 118,700 tonnes since 1950, compared to only 23,700 tonnes reported to FAO by local fisheries authorities. Overall, total catches appear to be steadily decreasing from approximately 2,800 t·year-1 in 1950 to 1,200 t·year-1 by 2008, interrupted by a peak catch of over 3,000 t·year-1 in 1975 (Figure 6a and Appendix Table A1). This decrease seems linked to the decline in both fishers and vessel numbers, but also to declines in fish abundance along the Corsican coast.

Official statistics likely accounted for commercial (artisanal) fisheries only, that is, red spiny lobster and bottom-trawl fisheries. Recreational fisheries by Corsicans, or by tourists, were not considered by official authorities. Finally, we highlighted the existence of discards (for red lobster and bottom-trawl fisheries), which are generally not included in reported statistics (Zeller et al., 2011).

This improved accounting of total catches (versus reported commercial landings) is also evident in the improved taxonomic accounting provided by our study (Figure 6b). Data reported by FAO on behalf of Corsica, besides being of poor quality, also had a poor taxonomic breakdown. Species present in these official data were reported as arbitrary, according to the local fisheries literature. In contrast, we have been able to assign catches to over 30 taxa, of which each had catches allocated in accordance to the literature (Figure 6b and Appendix Table A2).

This study provides an estimate of total fisheries catches in Corsican waters since 1950, and although some sectors such as the pelagic fisheries have not been dealt with in detail, two major conclusions emerge from our work: (1) historical events, changes in gear and emergence of new fisheries illustrate that, despite being assumed to be one of the areas of the Mediterranean with the lowest fishing pressure (Riutort, 1994; Relini et al., 1999), Corsican waters may be exposed to higher fishing pressure than previsously assumed; and (2) our results suggest that Corsicans seem to be much more involved in marine resource exploitation than it appears in the literature and in official statistics.

ACKNOWLEDGEMENT

This is a product of the Sea Around Us project, a scientific collaboration between the University of British Columbia and the Pew Environment Group. We thank Jacques Bertrand (Ifremer) for sharing information and knowledge.